1. Field of the Invention
This invention is related to the field of optical fiber pumping systems. More particularly, the invention is directed to a system and apparatus that enables swapping of optical amplifier pumps from an onboard optical fiber system while the optical fiber system is operating.
2. Description of the Related Art
Typical optical fiber pumping systems include a xe2x80x9csoft-failxe2x80x9d design that uses redundant pumps to prevent downtime when one of the pumps fails. For example, a optical fiber pumping system which includes at least two pump lasers that feed their power into a conventional coupler that combines the outputs of each pump laser into a single output. In this manner, the failure of one of the pump lasers results in a corresponding percentage decrease in the amplification ability of the optical fiber pumping system. For example, if the optical fiber pumping system includes two pump lasers, failure of one of the pump lasers will typically result in an output of only fifty percent of the designed output. These systems often include monitors that indicate when a pump has failed, thus, when a pump has failed, an operator may take the entire optical pumping system off-line and replace the failed pump laser with a new pump laser.
Other conventional optical fiber pumping systems provide protective switching that re-route the signal to other parallel optical fiber pumping systems around the failed optical fiber pumping system. Such systems completely remove the load from the optical fiber pumping system and enable a technician to remove and service the entire optical fiber pumping system. Such systems require redundant optical fiber pumping systems which adds a great deal of expense.
The invention is an optical fiber pumping system that enables a hot swap of a failed pump. The optical fiber pumping system includes an external connector that enables an external pump laser to be connected to the optical fiber pumping system. The external connector communicates with a pump multiplexer that also receives an input from the on-board pump laser. The pumping system may also include an onboard connector that is positioned between the on-board pump laser and the pump multiplexer to break the connection between a failed on-board pump laser and the pump multiplexer.
The optical fiber pumping system of the present invention may also include a gain control system that coordinates the shut down of the on-board pump laser with the power up of an external pump laser system.
The external pump laser system may include a plurality of pump lasers whose combined or averaged output wavelength approximates the wavelength of the on-board pump laser.
The external pump laser system may include inexpensive but high power sources since the reliability of the external power source does not need to be high.
Additionally, any number of on-board pumps may be replaced using the external pumping system.